JPH0411125Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air blowout device that uses compressed air to check the presence or absence of a hole and its depth, and to remove foreign matter in the hole.

[Prior Art] When tapping or drilling is divided and carried out over several stations, if the pre-processing is not completed completely due to damage caused by the worker, trouble may occur in the post-processing. At such times, an air blowout device is used to check whether the hole has been machined to a predetermined depth and to remove foreign matter such as chips from the hole that has been machined (hereinafter simply referred to as hole). A conventional air blowout device will be explained below.

(1) A conventional air blowout device, as shown in Fig. 1, has a test bar 1 that blows out compressed air;
It consists of an air blow unit made up of a spring 5 and an air cylinder or hydraulic cylinder 4 that drives the unit. The hydraulic cylinder 4 is the air case 2 of the air blow unit.
The test bar 1 is moved forward and brought close to the hole 6 of the workpiece 3 while jetting compressed air from the tip of the test bar 1, and foreign matter near the entrance of the hole 6 is first removed. Then, move the air case 2 forward further and test bar 1
into hole 6. At this time, if the hole is not formed or is shallower than a predetermined size, the test bar 1 will collide with the workpiece 3 and the test bar 1 will stop. However, as the air blow unit moves forward, the spring 5 bends and the limit switch 8 attached to the test bar 1 hits the abnormality detection limit switch 7 attached to the air case 2. When the limit switch 7 is operated, the operation of the hydraulic cylinder 4 is stopped and an abnormality in the hole 6 is notified.

(2) A moving table that moves back and forth is provided with a series of parallel cylinders, and the cylinders are filled with oil or other liquid, so that one of the plurality of cylinders is
Japanese Utility Model Publication No. 44-13875 discloses an inspection device in which one piston is provided with a rod that interlocks with a detector, and each of the remaining pistons is provided with a detection rod.

(3) A technique for detecting the displacement of a sliding body with an air injection nozzle at its tip and whose rear end is pressed by a spring using an air switch is disclosed in U.S. Pat.

[Problems to be solved by the invention] However, in the case of the air blowout device (1), since a large number of holes are each inspected with a test bar equipped with an abnormality detection limit switch, the installation location of the limit switch is restricted. If the mutual spacing between the plurality of holes is narrow, it may become impossible to install an abnormality detection limit switch, and since there are a large number of limit switches, failures are likely to occur.
Furthermore, since the structure is such that a force proportional to the amount of deflection of the spring is applied to the test bar when an abnormality occurs in the hole, there is a problem that the tip of the test bar may become deformed.

The air blowout device (2) converts the displacement of the test bar into the displacement of the piston using liquid as a medium and using the ratio of cylinder diameters. When increasing the sensitivity of the device, there is a problem in that the sensitivity is greatly restricted due to the size of the cylinder, etc. Furthermore, when the test bar enters the hole of the workpiece and receives an impact, the medium that transmits the displacement of the test bar is liquid, so it does not contract and does not absorb the impact. the result,
The problem with the test bar is that it deforms. Furthermore, two types of media are required: air is the medium for blowing out the dust in the holes of the workpiece, and liquid is the medium for transmitting the movement displacement.

In the air blowout device (3), when the nozzle enters the hole in the workpiece and stops due to impact, the nozzle receives a force from the spring, that is, a large force proportional to the amount of movement of the nozzle acts on the nozzle. If there are foreign objects such as burrs on the test bar, the test bar may get caught in them. As a result, there was a problem that the work itself could be damaged in such cases.

[Means and actions for solving the problems] The gist of the present invention, which aims to solve the above problems, is to blow out compressed air from the tip to eliminate foreign objects in the hole 6 drilled in the workpiece 3. This air blowout device detects whether or not the hole 6 drilled in the workpiece 3 has a predetermined depth by advancing the air chamber 2 into which the test bar 1 for removing the workpiece 3 is slidably inserted. In addition, the portion of the test bar 1 that penetrates the first air chamber A of the three air chambers 2 is always filled with the compressed air in the first air chamber A regardless of the sliding movement of the test bar 1. Through holes 10 and 19 are provided to guide the air to the tip of the test bar 1 so as to remove foreign matter in the hole 6 of the workpiece, and the second air in the three air chambers 2 of the test bar 1 is A drop-off prevention piece is provided at the end inserted into the P chamber, and has a cross section larger than the cross section of the test bar, and is pressed against the wall surface by the air pressure of the second air chamber when the test bar starts moving forward, and further The test bar 1 is configured to transfer the compressed air in the second air chamber P to the third air chamber only when the test bar 1 is obstructed from moving forward and retreats in the third air chamber 2. Through holes 11, 12, and 13 are provided to guide the test bar 1 into the chamber D, and the forward movement of the test bar 1 is inhibited and the compressed air in the second air chamber P is moved backward within the three air chambers 2. The air blowout is characterized by being provided with a pressure change detection section that detects a pressure change in the third air chamber D when the air passes through the through holes 11, 12, and 13 and flows into the third air chamber D. It's in the device.

[Embodiment] Next, the configuration of an embodiment of the present invention will be explained with reference to FIGS. 2 and 3. The test bar 1 is slidably held in an air case 2, which is supported by a slidable support device 9 so as to be movable by a hydraulic cylinder 4. Air case 2 is A with bulkheads 15 and 18.
It is divided into three air chambers: (first air chamber), D (third air chamber), and P (second air chamber), and compressed air enters chamber A (first air chamber). , the hole 10 communicates with an air outlet 19 at the tip of the test bar 1. Compressed air also enters the P chamber (second air chamber), the 14 sides of the brim of the test bar 1 are pressed against the air case bulkhead 15, and the D chamber (third air chamber)
is in communication with the pressure switch 16. The pressure switch 16 corresponds to a pressure change detection section, and the pressure switch 16 corresponds to a pressure change detection section.
4 corresponds to a falling-off prevention piece. Holes 11, 12, and 13 are drilled in the test bar 1 so that the P chamber (second air chamber) and D chamber (third air chamber) communicate when the test bar moves toward the hydraulic cylinder 4. There is. Seals 17 are inserted between the test bar 1 and the air case 2 to prevent compressed air from leaking. Note that several test bars 1 can be provided in the air case 2 at positions corresponding to the holes 6 of the workpiece 3.

Next, the operation of this embodiment will be explained. test bar 1
is pushed out to the workpiece 3 side by the air pressure of the P chamber (second air chamber), and the partition wall 1 of the air case 2 is pushed out by the brim surface 14.
It is pressed on 5 sides. In this state, compressed air in chamber P (second air chamber) cannot enter chamber D (third air chamber). Compressed air in chamber A (first air chamber) passes through hole 10 to test bar 1
The air is ejected from the air outlet 19 at the tip of the air outlet. The test bar 1 is advanced together with the air case 2 by the hydraulic cylinder 4 and inserted into the hole 6 of the workpiece 3 to remove foreign matter and inspect the depth of the hole. If hole 6
If the test bar 1 is not opened properly, the tip of the test bar 1 collides with the workpiece 3, and when the air case 2 is further advanced by the cylinder 4, the test bar 1
Only the air case 2 moves forward while remaining stationary. Then, the mutual positions of the test bar 1 and the air case 2 change as shown in FIG. chamber (third air chamber). The force pushing the test bar 1 toward the workpiece 3 is P·πa ² /4, which is equal to the force that the collar 14 receives from the air pressure in the P chamber (second air chamber) when the test bar 1 moves forward. , the force becomes P(πa ² /4−πb ² /4) due to the retreat of the collar 14. As a result, the force pushing the test bar 1 toward the workpiece 3 is reduced by the retreat of the collar 14.

The air pressure in chamber D (third air chamber), which rises as a result of the opening of the valve in the collar 14, is guided to the pressure switch 16 and converted into an electrical output, which is taken out as an abnormal signal, stops the operation of the hydraulic cylinder 4, and further alarms. It is a means of emitting. After detecting an abnormality, if you want to use the air blowout device again, open the P chamber (second air chamber).
P(πa ² /4-
πb ² /4) moves in the direction of the workpiece, the test bar automatically moves in the direction of the workpiece, the collar 14 and the partition wall 15 come into pressure contact, and the P chamber (second air chamber) and D chamber (third (air chamber) is blocked and the normal state returns. Here, a is the outer diameter of the test bar of the partition wall 15, b is the inner diameter of the hole 12, and C is the outer diameter of the collar 14. Several other test bars 1 also function in the same manner as described above.

[Effect of the invention] As explained above, the air blowout device of the invention acts on the drop-off prevention piece as the test bar retreats when it enters the hole drilled in the workpiece and stops due to impact. Reduce the force pushing the test bar toward the workpiece. Therefore, the air blowout device of the present invention has the effect that even if foreign matter such as burrs is present in the hole of the workpiece, the test bar will not get caught in it. As a result, the air blowout device of the present invention has excellent effects such as not damaging the workpiece itself. Next, the device of the present invention has the excellent effect of converting a subtle displacement of the test bar into a large pressure change and increasing the sensitivity of sliding displacement. Furthermore, the device of the present invention described above has the following features:
Since the medium for blowing out foreign matter in the holes of the workpiece and the medium for transmitting the movement displacement are both air, there is an effect that the apparatus can be simplified. Furthermore, when the device of the present invention has multiple test bars, it is possible to detect abnormal signals at one location, and simultaneous inspection of multiple holes is possible without the need to install one limit switch for each test bar. Since there are no test bars, more test bars can be provided than in the conventional device, and failures of the abnormality detection device are also reduced.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view showing a conventional air blowout device; Figs. 2 to 4 are drawings showing an embodiment of the air blowout device of the present invention; Fig. 2 is a partially sectional front view; FIG. 3 is a front sectional view of the main part of the test bar when the hole is in a normal state, and FIG. 4 is a front sectional view of the main part of the test bar when the hole is in an abnormal state. 1...Test bar, 2...Air case, 3...
Workpiece, 4... Hydraulic cylinder, 6, 10, 1
1, 12, 13... hole, 14... brim, 15...
Partition wall, 16...Pressure switch, A, D, P...
Room.

Claims (1)

[Claims for Utility Model Registration] 1. Three air chambers into which a test bar is slidably inserted, which ejects compressed air from the tip to remove foreign matter in a hole drilled in a workpiece, are moved forward to remove foreign matter from a hole drilled in the workpiece. It is an air blowout device for detecting whether or not a hole drilled in the test bar is at a predetermined depth, and the test bar is equipped with the test bar in the part that penetrates the first air chamber of the three air chambers of the test bar. A through hole is provided that always guides the compressed air in the first air chamber to the tip of the test bar so as to remove foreign matter in the hole of the workpiece regardless of the sliding of the bar. The end of the air chamber inserted into the second air chamber has a cross section larger than the cross section of the test bar, and when the test bar starts moving forward, it is crushed by the wall surface by the air pressure of the second air chamber and falls off. A prevention piece is provided on the test bar, and the test bar is configured to transfer the compressed air in the second air chamber to the third air chamber only when the test bar is obstructed from advancing and retreats within the three air chambers. A through hole is provided to guide the test bar into the air chamber, and the forward movement of the test bar is inhibited and the test bar retreats within the three air chambers, and the compressed air in the second air chamber passes through the through hole and enters the third air chamber. An air blowout device comprising a pressure change detection section that detects a pressure change in a third air chamber when air flows into the air chamber. 2. The air blowout device according to claim 1, wherein abnormal air pressure signals from several test bars are combined into one signal by providing an air chamber.